This appears to be an Amazon web site glitch. There are two HD 10 product codes (maybe more). If you simply search for “fire HD 10” the first entry will be an “Amazon’s Choice … Fire HD 10” . That product code , B01J6RPGKG , is backordered 4-6 months.

However, if you simply select from Fire Tablet navigation bar at the top of the page. ( select the HD 10 or select the another (e.g., HD 8) and then select HD 10 from there, then you will arrive in another product code, B01M6YJEAH. it is in stock at the same price ships and sold by Amazon.

Poking around a bit it seems as though the “Amazon Choice” option is the black version. If navigate in another way then it picks one that they actually have ( Blue ).